U.S. patent number 10,987,232 [Application Number 16/335,606] was granted by the patent office on 2021-04-27 for artificial knee joint replacement operation instrument.
This patent grant is currently assigned to KYOCERA CORPORATION. The grantee listed for this patent is KYOCERA Corporation. Invention is credited to Masahiko Hashida, Akinori Mori.
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United States Patent |
10,987,232 |
Hashida , et al. |
April 27, 2021 |
Artificial knee joint replacement operation instrument
Abstract
When using an artificial knee joint replacement operation
instrument, the amount of labor required to attach a tibial insert
trial to a patient is further reduced. An artificial knee joint
replacement operation instrument has a tibial trial attachment
instrument assembly used in an operation for replacing a patient's
knee joint with an artificial knee joint. The tibial trial
attachment instrument assembly includes a template to be attached
to a tibia, a keel punch guide to be joined to the tibia via the
template, a keel punch to be inserted into the tibia through the
keel punch guide, a keel punch handle for operating the keel punch,
and a tibial insert trial to be placed on the template, the tibial
insert trial being separate from the template.
Inventors: |
Hashida; Masahiko (Kyoto,
JP), Mori; Akinori (Kyoto, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
KYOCERA Corporation |
Kyoto |
N/A |
JP |
|
|
Assignee: |
KYOCERA CORPORATION (Kyoto,
JP)
|
Family
ID: |
1000005512872 |
Appl.
No.: |
16/335,606 |
Filed: |
September 27, 2017 |
PCT
Filed: |
September 27, 2017 |
PCT No.: |
PCT/JP2017/034968 |
371(c)(1),(2),(4) Date: |
March 21, 2019 |
PCT
Pub. No.: |
WO2018/062279 |
PCT
Pub. Date: |
April 05, 2018 |
Prior Publication Data
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|
|
Document
Identifier |
Publication Date |
|
US 20190298543 A1 |
Oct 3, 2019 |
|
Foreign Application Priority Data
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|
|
|
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Sep 28, 2016 [JP] |
|
|
JP2016-189481 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F
2/46 (20130101); A61B 17/1675 (20130101); A61F
2/4684 (20130101); A61B 17/1764 (20130101); A61B
17/56 (20130101); A61B 17/92 (20130101); A61F
2/461 (20130101); A61F 2/389 (20130101); A61F
2/38 (20130101); A61F 2/4603 (20130101); A61F
2002/4615 (20130101) |
Current International
Class: |
A61F
2/46 (20060101); A61B 17/92 (20060101); A61F
2/38 (20060101); A61B 17/17 (20060101); A61B
17/16 (20060101); A61B 17/56 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
|
2007-021200 |
|
Feb 2007 |
|
JP |
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2013-013732 |
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Jan 2013 |
|
JP |
|
5559437 |
|
Jul 2014 |
|
JP |
|
2012/083280 |
|
Jun 2012 |
|
WO |
|
Primary Examiner: Snow; Bruce E
Assistant Examiner: Hoban; Melissa A
Attorney, Agent or Firm: Volpe Koenig
Claims
The invention claimed is:
1. An artificial knee joint replacement operation instrument
comprising: a tibial trial attachment instrument assembly to be
used in an operation for replacing a patient's knee joint with an
artificial knee joint, the tibial trial attachment instrument
assembly including: a template to be attached to the patient's
tibia; a keel punch guide to be joined to the tibia via the
template; a keel punch to be inserted into the tibia through the
keel punch guide; a keel punch handle for operating the keel punch;
and a tibial insert trial to be placed on the template, the tibial
insert trial being separate from the template, wherein the tibial
trial attachment instrument assembly further comprising: a first
connection mechanism configured to enable the keel punch handle and
the keel punch to be attached to and detached from each other, and
prevent the keel punch handle from coming out from the keel punch,
wherein the first connection mechanism is further configured to
connect and disconnect the keel punch handle to and from the keel
punch by moving the keel punch handle relative to the keel punch in
a predetermined first direction that differs from an axial
direction of the keel punch handle, and wherein the first direction
is a rotational direction around an axis parallel to the axial
direction.
2. The artificial knee joint replacement operation instrument
according to claim 1, wherein the keel punch guide includes a
tubular portion that is provided to allow the keel punch to pass
therethrough and is arranged in alignment with the template, and a
passage through which a template handle for operating the template
passes when the template handle is removed from the template is
formed in an outer-circumferential portion of the tubular
portion.
3. The artificial knee joint replacement operation instrument
according to claim 1, wherein the tibial trial attachment
instrument assembly includes a spacer capable of being inserted
between the tibial insert trial and the template.
4. An artificial knee joint replacement operation instrument
comprising: a tibial trial attachment instrument assembly to be
used in an operation for replacing a patient's knee joint with an
artificial knee joint, the tibial trial attachment instrument
assembly including: a template to be attached to the patient's
tibia; a keel punch guide to be joined to the tibia via the
template; a keel punch to be inserted into the tibia through the
keel punch guide; a keel punch handle for operating the keel punch;
and a tibial insert trial to be placed on the template, the tibial
insert trial being separate from the template, wherein the tibial
trial attachment instrument assembly further comprising: a first
connection mechanism configured to enable the keel punch handle and
the keel punch to be attached to and detached from each other, and
prevent the keel punch handle from coming out from the keel punch,
wherein the first connection mechanism has a first protrusion
formed in one of the keel punch handle and the keel punch, and a
first connected portion formed in the other one of the keel punch
handle and the keel punch, and the first protrusion is connected to
and disconnected from the first connected portion by relative
movement of the keel punch handle and the keel punch, wherein the
first protrusion is provided at a leading end of the keel punch
handle, and has a rectangular shape in a cross-section orthogonal
to an axial direction of the keel punch handle, and the first
connected portion includes a first projection formed on an
inner-circumferential face of a tubular portion of the keel punch,
and wherein a pair of first projections is provided at a pitch of
180 degrees on the inner-circumferential face of the tubular
portion, and a hole portion having a cross-sectional shape that
matches a cross-sectional shape of the first protrusion is formed
within the tubular portion.
5. An artificial knee joint replacement operation instrument
comprising: a tibial trial attachment instrument assembly to be
used in an operation for replacing a patient's knee joint with an
artificial knee joint, the tibial trial attachment instrument
assembly including: a template to be attached to the patient's
tibia; a keel punch guide to be joined to the tibia via the
template; a keel punch to be inserted into the tibia through the
keel punch guide; a keel punch handle for operating the keel punch;
and a tibial insert trial to be placed on the template, the tibial
insert trial being separate from the template, wherein the tibial
trial attachment instrument assembly further comprising: a second
connection mechanism for enabling the keel punch handle and the
keel punch guide to be attached to and detached from each other,
and integrally connecting the keel punch handle to the keel punch
guide, wherein the second connection mechanism is configured to
connect and disconnect the keel punch handle to and from the keel
punch guide by moving the keel punch handle relative to the keel
punch guide in a predetermined second direction that differs from
an axial direction of the keel punch handle, and wherein the second
direction is a rotational direction around an axis parallel to the
axial direction.
6. The artificial knee joint replacement operation instrument
according to claim 5, wherein the second connection mechanism
includes a second protrusion formed in one of the keel punch handle
and the keel punch guide, and a second connected portion formed in
the other one of the keel punch handle and the keel punch guide,
and the second protrusion is connected to and disconnected from the
second connected portion by relative movement of the keel punch
handle and the keel punch guide.
7. An artificial knee joint replacement operation instrument
comprising: a tibial trial attachment instrument assembly to be
used in an operation for replacing a patient's knee joint with an
artificial knee joint, the tibial trial attachment instrument
assembly including: a template to be attached to the patient's
tibia; a keel punch guide to be joined to the tibia via the
template; a keel punch to be inserted into the tibia through the
keel punch guide; a keel punch handle for operating the keel punch;
and a tibial insert trial to be placed on the template, the tibial
insert trial being separate from the template, wherein the tibial
trial attachment instrument assembly further includes: a first
connection mechanism configured to enable the keel punch handle and
the keel punch to be attached to and detached from each other, and
prevent the keel punch handle from coming out from the keel punch;
and a second connection mechanism for enabling the keel punch
handle and the keel punch guide to be attached to and detached from
each other, and integrally connecting the keel punch handle to the
keel punch guide, further wherein displacing the keel punch handle
in one direction relative to the keel punch and the keel punch
guide cancels a connection between the keel punch handle and the
keel punch through the first connection mechanism, and connects the
keel punch handle to the keel punch guide through the second
connection mechanism, and wherein a first direction in which the
keel punch handle is displaced relative to the keel punch to
connect the keel punch handle to the keel punch through the first
connection mechanism and a second direction in which the keel punch
handle is displaced relative to the keel punch guide to connect the
keel punch handle to the keel punch guide through the second
connection mechanism are set to opposite directions.
Description
TECHNICAL FIELD
The present invention relates to an artificial knee joint
replacement operation instrument used in an operation for replacing
a patient's knee joint with an artificial knee joint.
BACKGROUND ART
In an artificial knee joint replacement operation for replacing a
patient's knee joint with an artificial knee joint, an operator
performs osteotomy on a distal portion of a femur using a surgical
instrument, and disposes a femoral component onto a cut bone
surface formed as a result of the osteotomy. The operator also
performs osteotomy on a proximal portion of a tibia using a
surgical instrument, and disposes a tibial component onto a cut
bone surface formed as a result of the osteotomy. When the tibial
component is attached, a tibial trial is tentatively attached to
the cut bone surface of the tibia. An optimal tibial component for
the patient is determined by referencing this tibial trial (e.g.
see Patent Documents 1 and 2).
In the configuration described in Patent Document 1, a base portion
trial (12) attached to an alignment handle (16) is aligned with a
proximal end (20) of a tibia (22). Next, a guide tower (14) is
driven into the tibia (22). Then, a keel punch (220), to which an
impaction handle (222) has been attached, is inserted into the
guide tower (14), and the keel punch (220) is driven into the tibia
(22). Here, the impaction handle (222) and the keel punch (220) are
locked to each other due to a leading end of a lever (308) of the
impaction handle (222) being caught on a lever-receiving notch
(246), which is formed at an upper end of the keel punch (220).
Upon the impaction handle (222) and the keel punch (220) being
inserted by a predetermined amount or more into the guide tower
(14), the lever (308) is pressed by the guide tower (14). As a
result, the lever (308) and the lever-receiving notch (246) of the
keel punch (220) are unlocked from each other. At the same time,
the lever (308) is caught on the guide tower (14). That is to say,
the impaction handle (222) and the guide tower (14) are locked with
each other. If the impaction handle (222) is pulled in this state,
the guide tower (14) is pulled out of the tibia (22) together with
the impaction handle (222). Meanwhile, the keel punch (220) is left
in the tibia (20).
In the configuration described in Patent Document 2, a tibial
bearing component (32A) is attached to a base plate (38A), which
corresponds to the base portion trial (12). According to the above
configuration, an optimal tibial component for a patient is
determined.
CITATION LIST
Patent Document
Patent Document 1: JP 2013-13732A
Patent Document 2: JP 5559437B
DISCLOSURE OF THE INVENTION
Problem to be Solved by the Invention
In the above configuration, instruments (the guide tower (14) and
the impaction handle (222)) for fixing the keel punch (220) to the
tibia (20), and the tibial bearing component (32A) need to be
prepared separately, and preparation of these instruments is
laborious.
The invention of this application aims to further reduce the amount
of labor required to attach a tibial insert trial to a patient,
when using an artificial knee joint replacement operation
instrument.
Means for Solving the Problem
(1) An artificial knee joint replacement operation instrument
according to an aspect of the present invention to achieve the
above-stated object includes: a tibial trial attachment instrument
assembly to be used in an operation for replacing a patient's knee
joint with an artificial knee joint, the tibial trial attachment
instrument assembly including: a template to be attached to the
patient's tibia; a keel punch guide to be joined to the tibia via
the template; a keel punch to be inserted into the tibia through
the keel punch guide; a keel punch handle for operating the keel
punch; and a tibial insert trial to be placed on the template, the
tibial insert trial being separate from the template.
According to this configuration, the template, the keel punch
guide, the keel punch, the keel punch handle, and the tibial insert
trial are prepared as a single assembly. Accordingly, these
instruments can be prepared collectively, which is less laborious
than in the case of preparing these instruments separately.
Accordingly, the amount of labor required to attach the tibial
insert trial to a patient can be further reduced.
(2) There are cases where the artificial knee joint replacement
operation instrument further includes a first connection mechanism
configured to enable the keel punch handle and the keel punch to be
attached to and detached from each other, and prevent the keel
punch handle from coming out from the keel punch.
According to this configuration, the first connection mechanism can
prevent the keel punch handle from coming out from the keel punch.
Also, the keel punch handle can be disconnected from the keel punch
when necessary. This makes it possible to suppress the case where
the keel punch handle and the keel punch become hindrances. As a
result, the amount of labor required to attach the tibial insert
trial to a patient can be further reduced.
(3) There are cases where the first connection mechanism is
configured to connect and disconnect the keel punch handle to and
from the keel punch by moving the keel punch handle relative to the
keel punch in a predetermined first direction that differs from an
axial direction of the keel punch handle.
According to this configuration, connection and disconnection
between the keel punch handle and the keel punch can be performed
with a simple configuration in which the keel punch handle and the
keel punch are relatively moved in the first direction. This makes
it possible to further reduce the amount of labor required to
attach the tibial insert trial to a patient.
(4) There are cases where the first direction is a rotational
direction around an axis parallel to the axial direction.
According to this configuration, connection and disconnection
between the keel punch handle and the keel punch can be performed
with a simple configuration in which the keel punch handle and the
keel punch are relatively rotated. This makes it possible to
further reduce the amount of labor required to attach the tibial
insert trial to a patient.
(5) There are cases where the first connection mechanism has a
first protrusion formed in one of the keel punch handle and the
keel punch, and a first connected portion formed in the other one
of the keel punch handle and the keel punch, and the first
protrusion is connected to and disconnected from the first
connected portion by relative movement of the keel punch handle and
the keel punch.
According to this configuration, connection and disconnection
between the first protrusion and the first connected portion can be
performed with a simple operation, that is, relative movement of
the keel punch handle and the keel punch.
(6) There are cases where the first protrusion is provided at a
leading end of the keel punch handle, and is formed to have a
rectangular shape in a cross-section orthogonal to an axial
direction of the keel punch handle, and the first connected portion
includes a first projection formed on an inner-circumferential face
of a tubular portion provided in the keel punch.
According to this configuration, the keel punch handle can be
connected to the keel punch by causing the first protrusion, which
has a protruding shape, to be caught on the first protrusion formed
in a hole in the keel punch. Also, the aforementioned connection
can be canceled by rotating the first protrusion relative to the
first projection.
(7) There are cases where a pair of the first projections is
provided at a pitch of 180 degrees on the inner-circumferential
face of the tubular portion, and a hole portion having a
cross-sectional shape that matches a cross-sectional shape of the
first protrusion is formed within the tubular portion.
According to this configuration, since the first protrusion can be
received by the pair of first projections, the connection strength
between the keel punch handle and the keel punch can be further
increased. With this configuration, the operator does not need to
pay attention to the connection strength between the keel punch
handle and the keel punch when handling the keel punch handle to
which the keel punch has been attached. As a result, the amount of
labor required to attach the tibial insert trial to a patient can
be further reduced.
(8) There are cases where the artificial knee joint replacement
operation instrument further includes a second connection mechanism
for enabling the keel punch handle and the keel punch guide to be
attached to and detached from each other, and integrally connecting
the keel punch handle to the keel punch guide.
According to this configuration, the second connection mechanism
enables the keel punch handle and the keel punch guide to be
integrally connected. This makes it possible to pull out the keel
punch guide using the keel punch handle. Also, the keel punch
handle can be disconnected from the keel punch guide when
necessary. This makes it possible to suppress the case where the
keel punch handle and the keel punch guide become hindrances. As a
result, the amount of labor required to attach the tibial insert
trial to a patient can be further reduced.
(9) There are cases where the second connection mechanism is
configured to connect and disconnect the keel punch handle to and
from the keel punch guide by moving the keel punch handle relative
to the keel punch guide in a predetermined second direction that
differs from an axial direction of the keel punch handle.
According to this configuration, connection and disconnection
between the keel punch handle and the keel punch guide can be
performed with a simple configuration in which the keel punch
handle and the keel punch guide are relatively moved in the second
direction. This makes it possible to further reduce the amount of
labor required to attach the tibial insert trial to a patient.
(10) There are cases where the second direction is a rotational
direction around an axis parallel to the axial direction.
According to this configuration, connection and disconnection
between the keel punch handle and the keel punch guide can be
performed with a simple configuration in which the keel punch
handle and the keel punch guide are relatively rotated. This makes
it possible to further reduce the amount of labor required to
attach the tibial insert trial to a patient.
(11) There are cases where the second connection mechanism includes
a second protrusion formed in one of the keel punch handle and the
keel punch guide, and a second connected portion formed in the
other one of the keel punch handle and the keel punch guide, and
the second protrusion is connected to and disconnected from the
second connected portion by relative movement of the keel punch
handle and the keel punch guide.
According to this configuration, a simple operation, that is,
relative movement of the keel punch handle and the keel punch guide
enables connection and disconnection between the second protrusion
and the second connected portion.
(12) There are cases where the artificial knee joint replacement
operation instrument further includes: a first connection mechanism
configured to enable the keel punch handle and the keel punch to be
attached to and detached from each other, and prevent the keel
punch handle from coming out from the keel punch; and a second
connection mechanism for enabling the keel punch handle and the
keel punch guide to be attached to and detached from each other,
and integrally connecting the keel punch handle to the keel punch
guide, wherein connection between the keel punch handle and the
keel punch through the first connection mechanism is canceled, and
also the keel punch handle is connected-to the keel punch guide
through the second connection mechanism.
According to this configuration, a single motion to displace the
keel punch handle in one direction relative to the keel punch and
the keel punch guide makes it possible to simultaneously cancel the
connection between the keel punch handle and the keel punch through
the first connection mechanism and connect the keel punch handle to
the keel punch guide through the second connection mechanism. This
makes it possible to further reduce the amount of labor required to
attach the tibial insert trial to a patient, through a reduction in
the amount of labor in handling the keel punch handle.
(13) There are cases where a direction in which the keel punch
handle is displaced relative to the keel punch to connect the keel
punch handle to the keel punch through the first connection
mechanism and a direction in which the keel punch handle is
displaced relative to the keel punch guide to connect the keel
punch handle to the keel punch guide through the second connection
mechanism are set to opposite directions.
According to this configuration, a configuration can be realized
that makes it possible to simultaneously perform an operation to
cancel the connection between the keel punch handle and the keel
punch through the first connection mechanism and an operation to
connect the keel punch handle to the keel punch guide through the
second connection mechanism. It is thus possible to further reduce
the amount of labor required to attach the tibial insert trial to a
patient, through a reduction in the amount of labor in handling the
keel punch handle.
(14) There are cases where the keel punch guide includes a tubular
portion that is provided to allow the keel punch to pass
therethrough and is arranged in alignment with the template, and a
passage through which a template handle for operating the template
passes when the template handle is removed from the template is
formed in an outer-circumferential portion of the tubular
portion.
According to this configuration, even in a state in which the space
around the tibia is small because, for example, the template has
been attached to a patient's tibia, the template handle can be
removed from the template through the passage. This makes it
possible to more easily operate the template handle. Accordingly,
the amount of labor required to attach the tibial insert trial to a
patient can be further reduced.
(15) There are cases where the tibial trial attachment instrument
assembly includes a spacer capable of being inserted between the
tibial insert trial and the template.
According to this configuration, the spacer for adjusting the
height of the tibial insert trial from the template is included in
the tibial trial attachment instrument assembly. This eliminates
the need for a laborious operation to prepare the spacer separately
from other members of the tibial trial attachment instrument
assembly. Accordingly, the amount of labor required to attach the
tibial insert trial to a patient can be further reduced.
Effects of the Invention
According to the present invention, the labor required to attach
the tibial insert trial to a patient can be further reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing an artificial knee joint
replacement operation instrument according to the present invention
and a portion of a patient's tibia.
FIG. 2 is a perspective view of a template handle, a template, a
keel punch guide, and the tibia.
FIG. 3 is a perspective view of the template.
FIG. 4A is a plan view of the template, and FIG. 4B is a front
elevational view of the template.
FIG. 5 is a perspective view showing a state in which the template
and the keel punch guide have been attached to a proximal portion
of the tibia.
FIGS. 6A and 6B are perspective views of the keel punch guide. FIG.
6C is a plan view of the keel punch guide. FIG. 6D is a front
elevational view of the keel punch guide.
FIG. 7 is a perspective view showing the template handle, the
template, a keel punch handle, the keel punch guide, and a keel
punch, together with the tibia.
FIG. 8A is a side view of a main portion of the keel punch handle.
FIG. 8B is a perspective view of a main portion of the keel punch
handle.
FIG. 9A is a plan view of the keel punch. FIG. 9B is a front
elevational view of a main portion, showing a state in which the
keel punch has been connected to the keel punch handle. FIG. 9C is
a cross-sectional view taken along a line IXC-IXC in FIG. 9B.
FIG. 10A is a side view of a main portion, showing a state in which
the keel punch has been connected to the keel punch handle. FIG.
10B is a cross-sectional view taken along a line XB-XB in FIG.
10A.
FIG. 11 is a perspective view showing a state in which the keel
punch handle has been connected to the keel punch guide.
FIG. 12A is a side view showing a state in which the keel punch
handle has been connected to the keel punch guide. FIG. 12B is a
cross-sectional view taken along a line XIIB-XIIB in FIG. 12A.
FIG. 13 is a side view showing a state in which the keel punch
handle has been connected to the keel punch, together with the keel
punch guide, and partially shows cross-sections of these
components.
FIG. 14A is a perspective view showing a state in which the
template is attached to the proximal portion of the tibia, before a
tibial insert trial is attached to the template. FIG. 14B is a
perspective view showing a state in which the template has been
attached to the proximal portion of the tibia, and the tibial
insert trial has been attached to the template.
FIG. 15A is a plan view of the template and the tibial insert
trial. FIG. 15B is a cross-sectional view taken along a line
XVB-XVB in FIG. 15A.
FIG. 16 is a perspective view of the tibial insert trial.
FIG. 17A is a perspective view showing the template and the tibial
insert trial before a spacer is attached thereto. FIG. 17B is a
perspective view showing the template and the tibial insert trial
to which the spacer has been attached.
FIG. 18A is a cross-sectional view showing a state in which the
spacer is arranged between the template and the tibial insert
trial, and shows a cross-section along a section corresponding to
the line XVB-XVB in FIG. 15A. FIG. 18B is a front elevational view
showing a state in which the spacer is arranged between the
template and the tibial insert trial.
FIG. 19 is a flowchart showing an example of a procedure of an
operation performed using a tibial trial attachment instrument
assembly.
FIGS. 20A and 20B are perspective views for describing an example
of an operation performed using the tibial trial attachment
instrument.
DESCRIPTION OF EMBODIMENTS
Hereinafter, modes for carrying out the present invention will be
described with reference to the drawings. Note that the present
invention is broadly applicable as an artificial knee joint
replacement operation instrument used in an operation for replacing
a knee joint with an artificial knee joint.
FIG. 1 is a perspective view showing an artificial knee joint
replacement operation instrument 1 according to the present
invention, and a portion of a patient's tibia 100. Referring to
FIG. 1, the artificial knee joint replacement operation instrument
1 is used in an artificial knee joint replacement operation for
replacing a patient's knee joint with an artificial knee joint.
This artificial knee joint replacement operation is used to restore
normal functionality of a knee of a patient whose knee joint has
deformed to a high degree due to gonarthrosis or chronic
rheumatism, for example.
In the artificial knee joint replacement operation, osteotomy is
performed on a proximal portion 101 of the patient's tibia 100, and
a flat cut bone surface 102 is thus formed. Next, a tibial
component suitable for the patient's tibia 100 is selected using a
tibial insert trial 18. Also, in the artificial knee joint
replacement operation, osteotomy is performed on a distal portion
of the patient's femur (not shown), and thereafter, a femoral
component suitable for the patient's femur is selected using a
femoral trial. Then, the tibial component is attached to the
proximal portion 101 of the tibia 100, and the femoral component is
attached to the distal portion of the femur. The tibial component
and the femoral component slide as the patient's knee bends,
thereby achieving smooth bending of the knee.
In the present embodiment, the terms "inner side" and "outer side"
refer respectively to the inner side and the outer side of the
patient's knee that is to be subjected to an artificial knee joint
replacement operation. An inward-outward direction X1 corresponds
to the left-right direction of the patient. The "front" and the
"rear" refer respectively to the front and the rear of the patient.
"Above" and "below" refer respectively to above and below for the
patient (lengthwise direction of the tibia 100). In this
embodiment, each component of the artificial knee joint replacement
operation instrument 1 is described based on a state of having been
attached to the proximal portion 101 of the patient's tibia
100.
The artificial knee joint replacement operation instrument 1
includes a tibial trial attachment instrument assembly 2.
The tibial trial attachment instrument assembly 2 is an instrument
assembly for attaching the tibial insert trial 18 to the tibia 100.
Component of the tibial trial attachment instrument assembly 2 are
accommodated in a single case, or are shipped as a single set from
a factory, and are handled as a single set in a medical
institution, for example.
The tibia trial attachment instrument assembly 2 has a template
handle 11, a template 12 that is to be attached to the patient's
tibia 100, a keel punch guide 13 to be joined to the tibia 100 via
the template 12, a drill 14, a drill stopper 15, a keel punch 16 to
be inserted into the tibia 100 through the keel punch guide 13, a
keel punch handle 17 for operating the keel punch 16, and a tibial
insert trial 18 that is separate from the template 12 and is to be
placed on the template 12, and a spacer 19 that can be inserted
between the tibial insert trial 18 and the template 12.
The above-listed components 11 to 19 of the tibial trial attachment
instrument assembly 2 are made of a material such as metal or a
synthetic resin. The above-listed components 11 to 19 are
preferably made of a biocompatible material, and it is preferable
that at least a portion that may come into contact with the patient
is made of a biocompatible material.
Note that the tibial trial attachment instrument assembly 2 need
only have any combination of at least two of the above-listed
components 11 to 19, and is not limited to the above configuration.
For example, in the artificial knee joint replacement operation
instrument 1, at least one of the template handle 11, the drill 14,
and the drill stopper 15 does not need to be included in the tibial
trial attachment instrument assembly 2.
FIG. 2 is a perspective view of the template handle 11, the
template 12, the keel punch guide 13, and the tibia 100. Referring
to FIGS. 1 and 2, the template handle 11 is used to operate the
template 12. In a state in which an operator is holding the
template handle 11, the template 12 is removably attached to a
leading end of the template handle 11.
The template handle 11 includes a holding portion 11a, which is to
be held by the operator, a lock lever 11b and a lock pin 11c, which
are supported by the holding portion 11a, and a connecting portion
11d, which is formed at a leading end of the holding portion
11a.
The holding portion 11a is formed into an elongated bar shape, and
is arranged in front of the proximal portion 101 of the tibia 100,
for example. The lock lever 11b is supported by the holding portion
11a at a front-end side portion thereof such that the lock lever
11b can slide relative to the holding portion 11a in the lengthwise
direction thereof. The lock pin 11c protrudes from the leading end
of the holding portion 11a. The lock pin 11c is a shaft-shaped
member, and is formed into a cylindrical shaft shape, for example.
This lock pin 11c is configured to be displaced integrally with the
lock lever 11b. The connecting portion 11d is arranged in on one
side of the lock pin 11c. The connecting portion 11d is provided as
a portion that is mated with a later-described connected portion 22
of the template 12. The connecting portion 11d is formed so as to
increase in width as it extends toward a leading end thereof, for
example.
As mentioned above, the template 12 is attached to the template
handle 11. The template 12 is a plate-shaped member that is placed
on the cut bone surface 102 of the proximal portion 101 of the
tibia 100, on which the keel punch guide 13 or the tibial insert
trial 18 is selectively placed, and through which the keel punch 16
is passed. The template 12 has a shape that substantially matches
the shape of the cut bone surface 102 when seen in a plan view.
Also, the template 12 is formed into a symmetrical shape in the
inward-outward direction X1.
FIG. 3 is a perspective view of the template 12. FIG. 4A is a plan
view of the template 12. FIG. 4B is a front elevational view of the
template 12. Referring to FIGS. 2, 3, 4A, and 4B, the template 12
has a central portion 20, side portions 21A and 21B, a connected
portion 22 and two pin hole portions 23 that are arranged in a
front portion of the template 12 for connection with the template
handle 11, a first spacer receiving portion 24 for receiving the
spacer 19, a guide receiving portion 25 for receiving the keel
punch guide 13, a keel punch insertion hole portion 26, stud
insertion hole portions 27a to 27d, and fixing pin insertion hole
portions 30a to 30f.
The central portion 20 is formed over a predetermined range
including the central portion of the template 12 in the
inward-outward direction X1. The central portion 20 is formed over
approximately the entire range of the template 12 in a front-rear
direction Y1. A front portion of the central portion 20 extends
substantially straight in the inward-outward direction X1. A
recessed portion that is recessed forward is formed in a rear
portion of the central portion 20. In the inward-outward direction
X1, the length of the central portion 20 is set substantially the
same as the length of the spacer 19. Also, two side portions 21A
and 21B are arranged respectively on the right side and the left
side of the central portion 20 in the inward-outward direction
X1.
The side portions 21A and 21B are portions each having an edge
portion formed into a curved shape that is close to an arc, when
viewed in a plan view. In this embodiment, in the inward-outward
direction X1, the length of each of the side portions 21A and 21B
is set shorter than the length of the central portion 20. The
connected portion 22 is provided at a front end of the central
portion 20.
The connected portion 22 is formed into a hole shape that matches
the shape of the connecting portion 11d at the leading end of the
template handle 11, and is open in an upper face of the template
12. The pin hole portions 23 are formed respectively on the right
side and the left side of the connected portion 22. The lock pin
11c of the template handle 11 is inserted into either one of the
pin hole portions 23. According to this configuration, the
connecting portion 11d of the template handle 11 is inserted into
the connected portion 22, and the lock pin 11c is inserted into one
of the pin hole portions 23, and thus the template 12 is connected
to the template handle 11. Also, the template handle 11 can be
removed from the template 12 by lifting up the template handle 11
from the template 12, in a state in which the lock pin 11c has been
pulled out of the one of pin hole portions 23.
The template 12 includes first to fourth upper faces 28a to
28d.
In the inward-outward direction X1, the first upper face 28a is
formed in front end portions of the side portions 21A and 21B of
the template 12, and also in the central portion 20. The first
upper face 28a is a flat face, and includes a front portion 28a1, a
rear portion 28a2, and a pair of side portions 28a3 that are
arranged in the same plane.
The front portion 28a1 of the first upper face 28a is provided in
the central portion 20 as a face that is continuous with a front
face of the central portion 20, and the connected portion 22 is
open in the front portion 28a1. A rear end edge of the front
portion 28a1 is formed into an arc shape to allow the keel punch 16
(see FIG. 1) to pass through. A rear portion 28a2 of the first
upper face 28a is arranged rearward of the front portion 28a1 of
the first upper face 28a. The rear portion 28a2 of the first upper
face 28a is formed in the central portion 20, and extends rearward.
A front end edge of the rear portion 28a2 of the first upper face
28a is formed into an arc shape to allow the keel punch 16 (see
FIG. 1) to pass through. The side portions 28a3 of the first upper
face 28a are provided in front end portions of the pair of side
portions 21A and 21B, and are arranged next to the front portion
28a1 of the first upper face 28a in the inward-outward direction
X1. The size of the side portions 28a3 of the first upper face 28a
is set smaller than the size of the front portion 28a1 of the first
upper face 28a.
The stud insertion hole portions 27a to 27d, through which studs
38a to 38d of the keel punch guide 13 are to pass, are formed in
the first upper face 28a and the second upper face 28b. The stud
insertion hole portions 27a and 27b are arranged in the second
upper face 28b. The stud insertion hole portions 27c and 27d are
arranged in the rear portion 28a2 of the first upper face 28a, near
the front end edge of the rear portion 28a2.
The second upper face 28b is also formed in the central portion 20.
The second upper face 28b is arranged between the front portion
28a1 and the rear portion 28a2 of the first upper face 28a. The
height position of the second upper face 28b is set lower than the
position of the first upper face 28a. The second upper face 28b is
formed into a symmetrical shape in the inward-outward direction X1.
An inner end edge of the second upper face 28b in the
inward-outward direction X1 is formed into an arc shape to allow
the keel punch 16 (see FIG. 1) to pass through.
The third upper face 28c is formed on the outer side of the second
upper face 28b in the inward-outward direction X1. The third upper
face 28c is formed into a symmetrical shape in the inward-outward
direction X1, and forms a portion of upper faces of the pair of
side portions 21A and 21B. The height position of the third upper
face 28c is set lower than the position of the second upper face
28b.
Side end walls 29A and 29B are formed in respective end portions of
the third upper face 28c in the inward-outward direction X1. The
side end walls 29A and 29B are wall portions that are arranged
close to a rear portion of the third upper face 28c, and protrude
upward. Each of the side end walls 29A and 29B has a step portion
in an intermediate portion thereof, and the height position of rear
portions of the side end walls 29A and 29B is set higher than the
height position of front portions of the side end walls 29A and
29B.
The fourth upper face 28d is arranged so as to be surrounded by the
third upper face 28c when seen in a plan view.
The fourth upper face 28d is formed into a symmetrical shape in the
inward-outward direction X1, and forms a portion of the upper faces
of the pair of side portions 21A and 21B. The height position of
the fourth upper face 28d is set lower than the position of the
third upper face 28c.
Out of the first upper face 28a to the fourth upper face 28d that
have the above configuration, the first upper face 28a includes a
first spacer receiving portion 24. The first spacer receiving
portion 24 is provided as a portion for receiving the spacer 19
(see FIG. 19) from below the spacer 19. The first spacer receiving
portion 24 is formed by at least a portion of the first upper face
28a. In this embodiment, the first spacer receiving portion 24 is
provided in the front portion 28a1 and the rear portion 28a2 of the
first upper face 28a. In this embodiment, the first spacer
receiving portion 24 is constituted by portions of the front
portion 28a1 and the rear portion 28a2 of the first upper face 28a
of the central portion 20, namely portions thereof on which the
spacer 19 can be put. According to this configuration, the spacer
19 is received by the first spacer receiving portion 24 in two
portions on the front end side and rear end side, and can thus be
received in a more stable orientation by the template 12. The guide
receiving portion 25 is arranged adjacent to the first spacer
receiving portion 24. The guide receiving portion 25 is provided as
a portion for receiving the keel punch guide 13.
The guide receiving portion 25 has a front portion 25a, a rear
portion 25b, and side portions 25c and 25d, and is configured to
support the keel punch guide 13 in a stable orientation by
supporting the keel punch guide 13 at four points (see FIG. 5).
The front portion 25a of the guide receiving portion 25 is formed
in the front portion 28a1 of the first upper face 28a. In this
embodiment, the rear portion 25b of the guide receiving portion 25
is formed in the rear portion 28a2 of the first upper face 28a. In
this embodiment, the side portions 25c and 25d of the guide
receiving portion 25 are formed in the third upper face 28c. The
side portions 25c and 25d of the guide receiving portion 25 are
constituted by the third upper face 28c on which the keel punch
guide 13 can be placed, around the boundary with the fourth upper
face 28d. The keel punch insertion hole portion 26 is formed
adjacent to the guide receiving portion 25 having the above
configuration.
The keel punch insertion hole portion 26 is formed as a portion
through which the keel punch 16 (see FIG. 1) passes when being
inserted into the proximal portion 101 of the tibia 100. The keel
punch insertion hole portion 26 has a circular portion 26a and a
pair of wing-shaped portions 26b that extend from this circular
portion. The circular portion 26a is a hole portion surrounded by
the rear end edge of the front portion 28a1 of the first upper face
28a, the front end edge of the rear portion 28a2, and the inner end
edge of the second upper face 28b. The two wing-shaped portions 26b
are substantially straight portions, when seen in a plan view, and
extend from the second upper face 28b to the fourth upper face 28d.
According to the above configuration, the keel punch insertion hole
portion 26 is formed into a substantially V-shape when seen in a
plan view. The fixing pin insertion hole portions 30a to 30f are
formed at positions that do not overlap the keel punch insertion
hole portion 26.
The fixing pin insertion hole portions 30a to 30f are provided as
penetrating portions through which fixing pins 31 (fixing member;
indicated by a dash-double dot line in FIG. 4) for fixing the
template 12 to the proximal portion 101 of the tibia 100 pass. A
plurality of fixing pin insertion hole portions 30a to 30f are
provided, and are provided in six portions in this embodiment. This
embodiment employs a configuration in which the positions of the
fixing pin insertion hole portions 30a to 30f differ from the
position of the spacer 19 (the first spacer receiving portion 24)
in the inward-outward direction X1.
The fixing pin insertion hole portions 30a and 30b are arranged at
end portions, in the inward-outward direction X1, of front portions
of the pair of side portions 21A and 21B of the template 12, and
are open in the third upper face 28c. The fixing pin insertion hole
portions 30c and 30d are arranged in the fourth upper face 28d
close to front portions thereof in the pair of side portions 21A
and 21B of the template 12, and are open in the fourth upper face
28d. The fixing pin insertion hole portions 30e and 30f are
arranged in the fourth upper face 28d close to rear portions
thereof in pair of side portions 21A and 21B of the template 12,
and are open in the fourth upper face 28d.
FIG. 5 is a perspective view showing a state in which the template
12 and the keel punch guide 13 have been attached to the proximal
portion 101 of the tibia 100. FIGS. 6A and 6B are perspective views
of the keel punch guide 13. FIG. 6C is a plan view of the keel
punch guide 13. FIG. 6D is a front elevational view of the keel
punch guide 13.
Referring to FIGS. 3, 5, and 6A to 6D, the keel punch guide 13 is
attached to the template 12 in a state of having been placed on the
cut bone surface 102 of the tibia 100. The keel punch guide 13 is a
member for guiding the keel punch 16 when the keel punch 16 is
inserted into the proximal portion 101. The keel punch guide 13 is
formed into a V-shape when seen in a plan view.
The keel punch guide 13 includes a tubular portion 131 and a pair
of wing portions 132, which are provided to allow the keel punch 16
to pass therethrough and are arranged in alignment with the
template 12.
The tubular portion 131 is provided as a portion through which a
tubular portion 161 of the keel punch 16 is to pass. In this
embodiment, the tubular portion 131 is formed into a cylindrical
shape. The tubular portion 131 includes a high-wall portion 34,
which is formed on the front side of the keel punch guide 13, and a
low-wall portion 35, which is formed on the rear side of the keel
punch guide 13.
The high-wall portion 34 is a portion formed into an arc shape
corresponding to approximately two-thirds of a circle, when seen in
a plan view, and is formed into a shape that protrudes forward. A
ball plunger 36, which serves as a positioning mechanism, is
provided in the high-wall portion 34. The ball plunger 36 is
provided to define the position of the keel punch handle 17 (see
FIG. 1) in the rotational direction, relative to the keel punch
guide 13. The ball plunger 36 has a configuration in which a spring
and a ball are accommodated in a housing that protrudes from the
high-wall portion 34 toward an outer-circumferential face of the
high-wall portion 34. The ball in the ball plunger 36 is partially
exposed in an inner-circumferential face of the high-wall portion
34. When subjected to an applied pressure, the ball in the ball
plunger 36 withdraws into the housing against elastic repulsive
force of the spring. A passage 37 is formed in a lower end portion
of a front end portion of the outer-circumferential portion of the
high-wall portion 34.
The passage 37 is a portion through which the connecting portion
11d of the template handle 11 for operating the template 12 passes
when the template handle 11 is removed from the template 12. This
passage 37 is arranged above the connected portion 22 of the
template 12 when the keel punch guide 13 is attached to the
template 12. The passage 37 is formed into a groove shape that
extends upward from a lower end of the high-wall portion 34, and is
open forward. The height and the width (the length in the
inward-outward direction X1) of the passage 37 are set such that
the connecting portion 11d of the template handle 11 can pass. The
low-wall portion 35 is arranged rearward of the high-wall portion
34.
The low-wall portion 35 is a portion formed into an arc shape
corresponding to approximately one-thirds of a circle, when seen in
a plan view, and is formed into a shape that protrudes rearward.
The height of the low-wall portion 35 is set lower than the height
of the high-wall portion 34. The high-wall portion 34 and the
low-wall portion 35 are connected to each other via the pair of
wing portions 132.
The pair of wing portions 132 are provided as portions through
which a later-described pair of wing portions 162 of the keel punch
16 passes. The pair of wing portions 132 is formed symmetrically in
the inward-outward direction X1. Each of the wing portions 132 has
a shape that extends rearward and outward in the inward-outward
direction X1 from a corresponding end portion of the high-wall
portion 34 in the inward-outward direction X1, and then extends
forward and inward in the inward-outward direction X1 to be
connected to a corresponding end portion of the low-wall portion
35. Upper faces of the wing portions 132 extend such that the
height positions thereof are lower as they extend farther from the
tubular portion 131. Lower faces of the wing portions 132 are
partially flat.
Studs 38a to 38d are formed in a bottom face of the tubular portion
131. The studs 38a to 38d are provided to fix the keel punch guide
13 to the proximal portion 101 of the tibia 100, and are formed
into shaft shapes extending downward from the tubular portion 131
so as to be able to be stuck into the proximal portion 101. The
studs 38a and 38b are formed in the high-wall portion 34 of the
tubular portion 131, and are arranged so as to be able to pass
through the corresponding stud insertion hole portions 27a and 27b
in the template 12. The studs 38c and 38d are formed in the
low-wall portion 35 of the tubular portion 131, and are arranged so
as to be able to pass through the corresponding stud insertion hole
portions 27c and 27d of the template 12.
The keel punch guide 13 is supported by the template 12, with the
studs 38a to 38d fixed to the tibia 100. Specifically, at a bottom
face of the high-wall portion 34 of the tubular portion 131, a
portion around the passage 37 is received by the front portion 25a
(the first spacer receiving portion 24) of the guide receiving
portion 25 of the template 12. Also, at a bottom face of the
low-wall portion 35 of the tubular portion 131, a portion around
the studs 38c and 38d is received by the rear portion 25b (the
first spacer receiving portion 24) of the guide receiving portion
25 of the template 12. Bottom faces of leading end portions of the
pair of wing portions 132 of the keel punch guide 13 are received
by the side portions 25c and 25d of the guide receiving portion
25.
Positioning protrusions 39a to 39d for positioning the keel punch
guide 13 on the template 12 are formed in a bottom face of the keel
punch guide 13. The positioning protrusions 39a and 39b are
portions that protrude downward from bottom faces of front portions
of the pair of wing portions 132. These positioning protrusions 39a
and 39b are attached at positions at which the positioning
protrusions 39a and 39b can sandwich the central portion 20 of the
template 12 in the inward-outward direction X1. The positioning
protrusions 39c and 39d are portions that protrude downward from
bottom faces of rear portions of the pair of wing portions 132.
These positioning protrusions 39c and 39d are attached at positions
at which the positioning protrusions 39c and 39d can sandwich the
central portion 20 of the template 12 in the inward-outward
direction X1.
According to the above configuration, as a result of the
positioning protrusions 39a and 39b and the positioning protrusions
39c and 39d being arranged so as to sandwich the central portion
20, the keel punch guide 13 is positioned in the inward-outward
direction X1 relative to the template 12. In a state in which the
keel punch guide 13 is arranged on the template 12, a hole portion
is formed in the proximal portion 101 of the tibia 100 by the drill
14.
The drill 14 is formed into a shaft shape, and has a diameter that
allows the drill 14 to pass through the tubular portion 131 of the
keel punch guide 13. A cutter portion is formed at a leading end of
the drill 14, and is configured to cut the proximal portion 101 of
the tibia 100. A connecting portion, which is to be connected to a
driving source such as an electric actuator (not shown), is formed
at a base end portion of the drill 14. The stopper 15 is disposed
in an intermediate portion of the drill 14 on the base end side.
The stopper 15 is provided to define the depth to which the drill
14 is inserted into the tubular portion 131 of the keel punch guide
13, i.e. the depth to which the drill 14 is inserted into the
proximal portion 101 of the tibia 100. The stopper 15 is provided
as a cylindrical element that is removable from the drill 14, and
has a cylindrical member and a holding member that are connected to
each other in a loose-fit state, via a shaft portion 15a (see FIG.
5). The holding portion has a pair of ring-shaped portions that
sandwich the cylindrical member in the thickness direction, and a
connecting portion that integrally connects the two ring-shaped
portions to each other. The connecting portion is configured to
integrally connect portions of outer-circumferential edge portions
of the two ring-shaped portions to each other, in the axial
direction of the cylindrical portion. The cylindrical member is
held by the holding member, in a state of being sandwiched by the
pair of ring-shaped portions of the holding member. An elongated
hole, into which the shaft portion 15a is inserted in a loose-fit
state, is provided in the cylindrical member. In a state in which
the cylindrical member is sandwiched and held between the pair of
ring-shaped portions of the holding member, the shaft portion 15a
is fixed to the holding member at a position at which the shaft
portion 15a is inserted into the elongated hole in the cylindrical
member. Thus, the cylindrical member is connected, in a loose-fit
state, to the holding member via the shaft portion 15a. A
protrusion is provided on an inner-circumferential face of the
cylindrical member, and is slidably fitted into a groove that is
provided on an outer-circumferential face of a portion of the drill
14 on the base end side and extends in the axial direction of the
drill 14. Note that an inner hole of the cylindrical member is
configured as an elliptical hole, with a direction in which the
protrusion extends serving as a major axis direction.
The stopper 15 can be removably disposed onto the drill 14 by
inserting the portion of the drill 14 on the base end side into
inner holes of the pair of ring-shaped portions of the holding
portion and the inner hole of the cylindrical member, in a state in
which the protrusion on the inner-circumferential face of the
cylindrical member is fitted into the groove in the drill 14. The
groove in the drill 14 is provided with a mating hole, which is
recessed inward into the drill 14 at a predetermined position on a
bottom portion of the groove. The stopper 15 is positioned in the
axial direction relative to the drill 14 at a position
corresponding to the aforementioned mating hole, in a state in
which the portion of the drill 14 on the base end side has been
inserted in the inner holes of the pair of ring-shaped portions and
the inner hole of the cylindrical member. More specifically, an
operation is performed to relatively move the cylindrical member
with respect to the holding member and the drill 14 to push the
cylindrical member toward the axis of the drill 14 so as to mate
the protrusion on the inner-circumferential face of the cylindrical
member with the aforementioned mating hole. At this time, the shaft
portion 15a fixed to the holding member is inserted, in a loose-fit
state, in the elongated hole in the cylindrical member, and the
portion of the drill 14 on the base end side is inserted in the
elliptical hole inside the cylindrical member. Accordingly,
relative movement of the cylindrical member with respect to the
drill 14 is allowed. Then, the protrusion on the
inner-circumferential face of the cylindrical member of the stopper
15 is mated with the mating hole in the drill 14, and thus, the
stopper 15 is positioned in the axial direction relative to the
drill 14. The drill 14 is inserted into the keel punch guide 13
until the stopper 15 comes into contact with an opening edge
portion 131a of the high-wall portion 34 of the tubular portion 131
of the keel punch guide 13. After a preparatory hole has been
formed in the proximal portion 101 of the tibia 100 by the drill
14, the keel punch 16 attached to the keel punch handle 17 is
inserted, through the keel punch guide 13, into the proximal
portion 101 of the tibia 100, as shown in FIG. 7.
FIG. 7 is a perspective view showing the template handle 11, the
template 12, the keel punch handle 17, the keel punch guide 13, and
the keel punch 16, together with the tibia 100. FIG. 8A is a side
view of a main portion of the keel punch handle 17. FIG. 8B is a
perspective view of the main portion of the keel punch handle 17.
Referring to FIGS. 7, 8A, and 8B, the keel punch handle 17 is used
by an operator to operate the keel punch 16, and is also used by an
operator to operate the keel punch guide 13. The keel punch handle
17 is an elongated member that extends axially.
The keel punch handle 17 has a flat portion 41 and a shaft portion
42.
The flat portion 41 is a flat plate-shaped portion formed in a base
end portion of the keel punch handle 17, and extends orthogonally
to the axial direction of the shaft portion 42. The flat portion 41
is a portion that is to be hit with a hammer by an operator when
driving the keel punch 16 into the tibia 100 using the hammer, for
example. The shaft portion 42 extends downward from the flat
portion 41.
The shaft portion 42 has a grip portion 43, a second stopper 44,
and an insertion end portion 45 that is formed on a leading end
side of the second stopper 44.
The grip portion 43 is an elongated portion that is to be gripped
by an operator, and an intermediate portion, in the axial
direction, of the grip portion 43 bulges radially outward. The flat
portion 41 is arranged in a base end portion of the grip portion
43, and the second stopper 44 is arranged in a leading end portion
of the grip portion 43.
The second stopper 44 is provided as a circular plate-shaped
portion that is to be received by the opening edge portion 131a of
the tubular portion 131, and extends in a direction orthogonal to
the axial direction of the keel punch handle 17. As a result of the
second stopper 44 being received by the opening edge portion 131a,
the position of the keel punch handle 17 in the axial direction
relative to the keel punch guide 13 is defined.
The insertion end portion 45 includes a portion that is to be
inserted into the tubular portion 161 of the keel punch 16. The
insertion end portion 45 is provided as a portion that is to be
inserted into the tubular portion 131 of the keel punch guide
13.
The insertion end portion 45 has first to fourth portions 45a to
45d.
The first portion 45a is a circular column-shaped portion that is
continuous with the second stopper 44. Connected portions 45f are
provided on an outer-circumferential face of the first portion 45a.
The connected portions 45f are groove-shaped portions into which
the ball in the ball plunger 36, which is a mechanism for
positioning the keel punch guide 13, is fitted. The connected
portions 45f extend in the axial direction of the keel punch handle
17, and are open in a lower end face of the first portion 45a. One
or more (in this embodiment, four) connected portions 45f are
provided at an even pitch in the circumferential direction of the
first portion 45a.
When the ball in the ball plunger 36 has entered a connected
portion 45f, and the value of the torque that acts on the keel
punch handle 17 is a predetermined value or less, the ball in the
ball plunger 36 restricts relative rotation of the keel punch guide
13. The second portion 45b extends from a leading end of the first
portion 45a.
The second portion 45b is formed into a circular column shape with
a diameter smaller than the diameter of the first portion 45a, and
is configured to be arranged within the tubular portion 131 of the
keel punch guide 13. A leading end face of the second portion 45b
includes a first stopper 40, which is to be received by the opening
edge portion 161a of the tubular portion 161 of the keel punch 16.
The first stopper 40 is a flat face. The third portion 45c extends
from a leading end of the second portion 45b.
The third portion 45c is a narrow shaft-shaped portion, and has a
diameter that is set smaller than the diameter of the second
portion 45b. The fourth portion 45d is formed at a leading end of
the third portion 45c. The fourth portion 45d constitutes a leading
end portion of the keel punch handle 17, and also constitutes a
portion of a later-described first connection mechanism 46.
Next, a description will be given of a more detailed configuration
of the keel punch 16 that is operated by the keel punch handle 17.
FIG. 9A is a plan view of the keel punch 16. FIG. 9B is a front
elevational view of a main portion, showing a state in which the
keel punch 16 has been connected to the keel punch handle 17. FIG.
9C is a cross-sectional view taken along a line IXC-IXC in FIG. 9B.
FIG. 10A is a side view of a main portion, showing a state in which
the keel punch 16 has been connected to the keel punch handle 17.
FIG. 10B is a cross-sectional view taken along a line XB-XB in FIG.
10A.
Referring to FIGS. 7, 9A to 9C, 10A, and 10B, the keel punch 16 is
provided to form a hole portion for embedding a stud of a tray (not
shown) of the tibial component into the proximal portion 101 of the
tibia 100, for example. The keel punch 16 is driven into the
proximal portion 101 in which a preparatory hole has been formed by
the drill 14. The keel punch 16 is formed into a V-shape when seen
in a plan view. The keel punch 16 is formed symmetrically in the
internal-external direction X1.
The keel punch 16 has the tubular portion 161 and the pair of wing
portions 162.
In this embodiment, the tubular portion 161 is formed into a
cylindrical shape, and one end portion thereof is open upward. A
portion of the tubular portion 161 on a leading end side is closed.
Positioning portions 163 are formed in the tubular portion 161. The
positioning portions 163 are provided to define the position of the
keel punch handle 17 in the circumferential direction relative to
the keel punch 16. A plurality of (in this embodiment, two)
positioning portions 163 are provided at equal intervals in the
circumferential direction of the tubular portion 161. In this
embodiment, the positioning portions 163 are through-holes formed
in the tubular portion 161.
The pair of wing portions 162 extends from an outer-circumferential
portion of the tubular portion 161. The pair of wing portions 162
is provided as plate-shaped members that have cutters in their
lower faces. The wing portions 162 are formed such that the lower
faces extend upward as they extend farther from the tubular portion
161, and also extend rearward as they extend farther from the
tubular portion 161.
The first connection mechanism 46 is configured to allow the keel
punch handle 17 and the keel punch 16, which have the above
configuration, to be attached to and detached from each other, and
to prevent the keel punch handle 17 from coming out from the keel
punch 16. In this embodiment, the first connection mechanism 46 is
arranged within the tubular portion 161 of the keel punch 16 when
the keel punch 16 is connected to the keel punch handle 17.
The first connection mechanism 46 includes a first protrusion 46a,
which is formed in either one of the keel punch handle 17 and the
keel punch 16 and serves as a first connecting portion, and first
projections 46b, which are formed in the other one of the keel
punch handle 17 and the keel punch 16 and serve as a first
connected portion.
More specifically, the first protrusion 46a is formed in either one
of the insertion end portion 45 and the tubular portion 161, and
the first projections 46b that are to be connected to the first
protrusion 46a are formed in the other one of the insertion end
portion 45 and the tubular portion 161. In this embodiment, the
first protrusion 46a is formed in the fourth portion 45d of the
insertion end portion 45, and the first projections 46b are formed
in the tubular portion 161. Note that the first projections (first
connected portion) may be formed in the fourth portion 45d of the
insertion end portion 45, and the first protrusion (first
connecting portion) may be formed in the tubular portion 161.
The first protrusion 46a is provided as a leading end portion of
the keel punch handle 17. In this embodiment, the fourth portion
45d of the insertion end portion 45 is formed by the first
protrusion 46a. The first protrusion 46a is arranged within an area
surrounded by an outline of the second portion 45b when seen from
below. The first protrusion 46a is formed into an elongated
rectangular column shape, and has a rectangular outline portion in
its cross-section orthogonal to the axial direction of the keel
punch handle 17. The first protrusion 46a is arranged coaxially
with the first portion 45a to the third portion 45c of the
insertion end portion 45. In this embodiment, the first protrusion
46a is formed into an elongated shape with a lengthwise direction
being the lengthwise direction of the flat portion 41 (the
left-right direction in FIG. 9B), and a widthwise direction being
the widthwise direction of the flat portion 41 (the direction
orthogonal to the paper plane in FIG. 9B), when seen from the
side.
The first projections 46b are formed on an inner-circumferential
face 164 of the tubular portion 161, within the tubular portion 161
of the keel punch 16. The first projections 46b protrude inward of
the tubular portion 161 from the inner-circumferential face 164 so
as to partially block the inner-circumferential face 164, which has
a circular shape, of the tubular portion 161, when seen in a plan
view. In this embodiment, the first projections 46b are configured
to allow the first protrusion 46a to pass between the first
projections 46b when the first protrusion 46a is at a predetermined
position in the circumferential direction of the keel punch 16, and
to restrict the first protrusion 46a from passing between the first
projections 46b when the first protrusion 46a is at another
position in the circumferential direction.
In this embodiment, the first projections 46b are formed
symmetrically with respect to each other when seen in a plan view,
and have a shape that includes a portion of a circle. More
specifically, one of the first projections 46b has an outline shape
demarcated by a line that extends straight to connect two points on
the inner-circumferential face 164 when seen in a plan view, and a
portion of the inner-circumferential face 164 that is demarcated by
this line. The other one of the first projections 46b has a similar
shape. Thus, the first projections 46b are provided to form a pair
at a pitch of 180 degrees on the inner-circumferential face 164 of
the tubular portion 161. According to this configuration, a passage
hole portion 46c is formed in the tubular portion 161, the passage
hole portion 46c having a cross-sectional shape that matches the
cross-sectional shape (elongated rectangular shape) of the first
protrusion 46a. The thickness of the first projections 46b (the
thickness of the keel punch 16 in the axial direction) is set
smaller than the length of the third portion 45c of the insertion
end portion 45 of the keel punch handle 17.
Also, the first connection mechanism 46 includes a ball plunger
46d, which serves as a positioning mechanism. The ball plunger 46d
is provided to define the position of the keel punch handle 17 in
the rotational direction relative to the keel punch 16. The ball
plunger 46d has a configuration in which a spring and a ball are
accommodated in a space formed in the first protrusion 46a. The
ball in the ball plunger 46d is partially exposed in a side face of
the first protrusion 46a that has a smaller width. When subjected
to an applied pressure, the ball in the ball plunger 46d withdraws
into the first protrusion 46a against elastic repulsive force of
the spring. The ball in the ball plunger 46d is configured to mate
with either one of the positioning portions 163 within the tubular
portion 161, and this mating can notify an operator that the keel
punch handle 17 has reached a locking position relative to the keel
punch 16.
According to the above configuration, when the keel punch handle 17
is connected to the keel punch 16, that is, when the insertion end
portion 45 is inserted into the keel punch 16, the first protrusion
46a is inserted into the tubular portion 161 so as to pass between
the first projections 46b. Then, the first stopper 40 is received
by the opening edge portion 161a of the tubular portion 161. When
the first stopper 40 is at the position at which it is received by
the opening edge portion 161a, the position of the first protrusion
46a is set on the distal side of the position of the space between
the pair of the first projections 46b within the tubular portion
161. The third portion 45c of the insertion end portion 45 is
located between the pair of first projections 46b.
In a state in which the insertion end portion 45 has been inserted
in the tubular portion 161, the first protrusion 46a is connected
to and disconnected from the first projections 46b through relative
displacement of the keel punch handle 17 and the keel punch 16. In
this embodiment, the aforementioned connection and disconnection
are performed by moving the keel punch handle 17 in a predetermined
first direction D1, which differs from the axial direction of the
keel punch handle 17, relative to the keel punch 16.
The first direction D1 includes a first connecting direction D11
for connecting the keel punch handle 17 to the keel punch 16, and a
first disconnecting direction D12 for canceling this connection
that is opposite to the first connecting direction D11. In this
embodiment, the first direction D1 is a rotational direction around
an axis parallel to the axial direction of the keel punch handle
17. Note that the first direction D1 may alternatively be another
direction, such as a helical direction around the aforementioned
axis.
In this embodiment, the keel punch handle 17 is connected (locked)
to the keel punch 16 as a result of the keel punch handle 17 being
rotated in the first connecting direction D11 by approximately 90
degrees relative to the keel punch 16, with the insertion end
portion 45 inserted in the tubular portion 161. At this time, a
portion of the first protrusion 46a faces the pair of first
projections 46b in the axial direction. Also, a recession formed in
the third portion 45c of the insertion end portion 45 and the first
protrusion 46a work together to hold each of the pair of first
projections 46b from two opposite sides. As a result, the keel
punch handle 17 and the keel punch 16 can be displaced integrally.
At this time, the ball in the ball plunger 46d is fitted to one of
the positioning portions 163 of the tubular portion 161.
If, in this state, the keel punch handle 17 is rotated by 90
degrees in the first disconnecting direction D12, the ball in the
ball plunger 46d rotates so as to come out from the positioning
portion 163. Then, the first protrusion 46b assumes an orientation
that allows the first protrusion 46a to pass between the pair of
projections 46b, and the keel punch handle 17 can be pulled out of
the keel punch 16.
FIG. 11 is a perspective view showing a state in which the keel
punch handle 17 has been connected to the keel punch guide 13. FIG.
12A is a side view showing a state in which the keel punch handle
17 has been connected to the keel punch guide 13. FIG. 12B is a
cross-sectional view taken along a line XIIB-XIIB in FIG. 12A. FIG.
13 is a side view showing a state in which the keel punch handle 17
has been connected to the keel punch 16, together with the keel
punch guide 13, and partially shows cross-sections of these
components.
Referring to FIGS. 6C, 11, 12A, 12B, and 13, a second connection
mechanism 47 is configured to enable the keel punch handle 17 to be
attached to and detached from the keel punch guide 13, and to
integrally connect the keel punch handle 17 to the keel punch guide
13. In this embodiment, when the keel punch guide 13 is connected
to the keel punch handle 17, the second connection mechanism 47 is
arranged within the tubular portion 131 of the keel punch guide
13.
The second connection mechanism 47 includes second protrusions 47a,
which serve as a second connecting portion formed in either one of
the keel punch handle 17 and the keel punch guide 13, and second
connected portions 47b and 47c, which are formed in the other one
of the keel punch handle 17 and the keel punch guide 13.
More specifically, the second protrusions 47a are formed in either
one of the insertion end portion 45 and the tubular portion 131,
and the second connected portions 47b and 47c that are to be
connected to the second protrusions 47a are formed in the other one
of the insertion end portion 45 and the tubular portion 131. In
this embodiment, a pair of second protrusions 47a is formed in the
second portion 45b of the insertion end portion 45, and the second
connected portions 47b and 47c are formed in the tubular portion
131. Note that the number of second protrusions 47a and the number
of second connected portions 47b and 47c may be one. A
configuration may alternatively be employed in which the second
connected portions are formed in the second portion 45b of the
insertion end portion 45, and the second protrusions (second
connecting portions) are formed in the tubular portion 131.
The second protrusions 47a are small piece portions that are formed
on an outer-circumferential face of the second portion 45b of the
insertion end portion 45 and protrude radially outward from the
second portion 45b. The second protrusions 47a are arranged at an
even pitch of 180 degrees in the circumferential direction of the
keel punch handle 17. The second protrusions 47a are aligned with
each other at positions distant, on the second stopper 44 side,
from the first protrusion 46a in the axial direction of the keel
punch handle 17. The second protrusions 47a extend in the widthwise
direction of the first protrusion 46a (the left-right direction in
FIG. 13). When the keel punch handle 17 is connected to the keel
punch 16 (i.e. at the time shown in FIG. 13), the second
protrusions 47a are located outside of the keel punch 16.
The second connected portions 47b and 47c are formed on an
inner-circumferential face of the tubular portion 131 of the keel
punch guide 13. The second connected portion 47b is arranged in the
high-wall portion 34 of the tubular portion 131, and the second
connected portion 47c is arranged in the low-wall portion 35 of the
tubular portion 131.
The second connected portion 47b is arranged on the lower side of
the inner-circumferential face of the high-wall portion 34, and is
formed into a shape protruding radially inward from this
inner-circumferential face. The second connected portion 47c is
arranged over the substantially entire area of an
inner-circumferential face of the low-wall portion 35, and is
formed into a shape protruding radially inward from this
inner-circumferential face. In this embodiment, the height (the
length in the axial direction) of the second connected portion 47b
and the height (the length in the axial direction) of the second
connected portion 47c are set to substantially the same length. The
second connected portions 47b and 47c are formed substantially
symmetrically in the front-rear direction Y1.
The second connected portion 47b includes a vertical groove portion
47d and a lateral groove portion 47e. The second connected portion
47c includes a vertical groove portion 47f and a lateral groove
portion 47g.
The vertical groove portions 47d and 47f are groove portions that
extend in the axial direction of the tubular portion 131, and have
shapes that are open in the axial direction of the tubular portion
131 and radially inward. The groove width of the vertical groove
portions 47d and 47f (the length of the tubular portion 131 in the
circumferential direction) is set such that the corresponding
second protrusions 47a can pass therethrough. The groove width of
the vertical groove portion 47d (see FIG. 6C) is set such that
projections 165 formed on the opening end side of the keel punch 16
can pass therethrough. The vertical groove portions 47d and 47f are
provided as portions through which the second protrusions 47a can
pass therethrough in the axial direction of the tubular portion
131. The arrangement pitch of the vertical groove portions 47d and
47f in the circumferential direction of the tubular portion 131 are
set to be the same as the arrangement pitch of the second
protrusions 47a in the circumferential direction of the keel punch
handle 17. In this embodiment, the vertical groove portions 47d and
47f are arranged in a front end portion and a rear end portion,
respectively, of the inner-circumferential face of the tubular
portion 131. The lateral groove portion 47e is formed to as to
intersect the vertical groove portion 47d, and the lateral groove
portion 47g is formed so as to intersect the vertical groove
portion 47f.
The lateral groove portions 47e and 47g are provided to be mated
with the corresponding second protrusions 47a, thereby integrally
connecting the keel punch handle 17 to the keel punch guide 13. The
lateral groove portions 47e and 47g are groove portions that extend
in the circumferential direction of the tubular portion 131, and
extend so as to intersect (in this embodiment, so as to be
orthogonal to) the corresponding vertical groove portions 47d and
47f. Thus, the lateral groove portions 47e and 47g span both sides
of the corresponding vertical groove portions 47d and 47f in the
circumferential direction. In this embodiment, the lateral groove
portions 47e and 47g are formed over the entire area of the
corresponding high-wall portion 34 and low-wall portion 35 in the
circumferential direction.
The distance in the axial direction of the keel punch guide 13 from
the opening edge portion 131a of the tubular portion 131 to the
lateral groove portions 47e and 47g is set to be substantially the
same as the distance in the axial direction of the keel punch
handle 17 from the second stopper 44 to the second protrusions
47a.
According to the above configuration, when the keel punch handle 17
is connected to the keel punch guide 13, that is, when the
insertion end portion 45 is inserted into the keel punch guide 13,
the second protrusions 47a pass through the corresponding vertical
groove portions 47d and 47f. Then, the second stopper 44 is
received by the opening edge portion 131a of the tubular portion
131. When the second stopper 44 is received by the opening edge
portion 131a, the second protrusions 47a can enter and exit from
the corresponding lateral groove portions 47e and 47g.
In a state in which the insertion end portion 45 has been inserted
in the tubular portion 131, the second protrusions 47a are
connected to and disconnected from the corresponding lateral groove
portions 47e and 47g of the second connected portions 47b and 47c
through relative displacement of the keel punch handle 17 and the
keel punch guide 13. In this embodiment, the aforementioned
connection and disconnection are performed by moving the keel punch
handle 17 in a predetermined second direction D2, which differs
from the axial direction of the keel punch handle 17, relative to
the keel punch guide 13.
The second direction D2 includes a second connecting direction D21
for connecting the keel punch handle 17 to the keel punch guide 13,
and a second disconnecting direction D22 for canceling this
connection that is opposite to the second connecting direction D21.
In this embodiment, the second direction D2 is a rotational
direction around an axis parallel to the axial direction of the
keel punch handle 17. Note that the second direction may
alternatively be another direction, such as a helical direction
around the aforementioned axis.
In this embodiment, the keel punch handle 17 is connected (locked)
to the keel punch guide 13 as a result of the keel punch handle 17
being rotated in the second connecting direction D21 by
approximately 90 degrees relative to the keel punch guide 13, with
the insertion end portion 45 inserted in the tubular portion 131.
At this time, the second protrusions 47a enter the corresponding
lateral groove portions 47e and 47g from the corresponding vertical
groove portions 47d and 47f. As a result, the second protrusions
47a are fitted into the corresponding lateral groove portions 47e
and 47g, and enter a state of being held from above and below by
the lateral groove portions 47e and 47g, respectively. Furthermore,
as a result of the ball in the ball plunger 36 in the keel punch
guide 13 being received by the connected portion 45f of the keel
punch handle 17, the keel punch handle 17 is positioned in the
circumferential direction relative to the keel punch guide 13. As a
result, the keel punch handle 17 and the keel punch guide 13 can be
displaced integrally.
If, in this state, the keel punch handle 17 is rotated by 90
degrees in the second disconnecting direction D22, the keel punch
handle 17 rotates such that the ball in the ball plunger 36 comes
out from the connected portion 45f. Also, the second protrusions
47a return to the corresponding vertical groove portions 47d and
47f. Thus, the keel punch handle 17 can be pulled out of the keel
punch guide 13.
In this embodiment, the first disconnecting direction D12 and the
second connecting direction D21 are the same direction. With this
configuration, it is possible to simultaneously cancel the
connection between the keel punch handle 17 and the keel punch 16
through the first connection mechanism 46 and connect the keel
punch handle 17 to the keel punch guide 13 through the second
connection mechanism 47, by displacing the keel punch handle 17 in
one direction relative to the keel punch 16 and the keel punch
guide 13.
The first connecting direction D11 is opposite to the second
connecting direction D21. That is to say, the direction (the first
connecting direction D11) in which the keel punch handle 17 is
displaced relative to the keel punch 16 in order to connect the
keel punch handle 17 to the keel punch 16 through the first
connection mechanism 46 is set to be opposite to the direction (the
second connecting direction D21) in which the keel punch handle 17
is displaced relative to the keel punch guide 13 in order to
connect the keel punch handle 17 to the keel punch guide 13 through
the second connection mechanism 47.
FIG. 14A is a perspective view showing a state in which the
template 12 is attached to the proximal portion 101 of the tibia
100, before the tibial insert trial 18 is attached to the template
12. FIG. 14B is a perspective view showing a state in which the
template 12 has been attached to the proximal portion 101 of the
tibia 100, and the tibial insert trial 18 has been attached to the
template 12. FIG. 15A is a plan view of the template 12 and the
tibial insert trial 18. FIG. 15B is a cross-sectional view taken
along a line XVB-XVB in FIG. 15A. FIG. 16 is a perspective view of
the tibial insert trial 18.
Referring to FIGS. 14A and 14B, 15A and 15B, and 16, the tibial
insert trial 18 is a member that is to be temporarily attached to
the proximal portion 101 of the tibia 100 when a tibial component
(not shown) is selected. The tibial insert trial 18 is formed into
a shape with a rear end portion of a central portion in the
inward-outward direction X1 being recessed forward.
The tibial insert trial 18 has a pair of tibial joint surfaces 48A
and 48B, which are arranged in the inward-outward direction X1, a
post 49, which is arranged between these tibial joint surfaces 48A
and 48B, and a bottom portion 50.
In this embodiment, a plurality of tibial insert trials 18 with
different shapes of the tibial joint surfaces 48A and 48B and
different shapes of the post 49 are provided. A tibial insert trial
18 will be described as an example. Note that other tibial insert
trials have the same configuration except that the shape of the
tibial joint surfaces and the shape of the post differ.
The two tibial joint surfaces 48A and 48B are portions that mimic
tibial joint surfaces of a tibial component, and have a recessed
shape similar to that of the tibial joint surfaces of the tibial
component. The pair of tibial joint surfaces 48A and 48B and the
post 49 face upward. The post 49 is a portion that mimics a post of
a tibial component, and has a columnar shape similar to that of the
post of the tibial component.
The bottom portion 50 has second rails 51A and 51B, and a second
spacer receiving portion 52.
The second rails 51A and 51B are formed in a pair of protrusions
53A and 53B that protrude downward from the bottom portion 50. The
two protrusions 53A and 53B are spaced apart in the inward-outward
direction X1, and are formed into tab shapes extending straight in
the front-rear direction Y1. The second rails 51A and 51B are
formed in an inner face of the pair of protrusions 53A and 53B,
respectively, in the inward-outward direction X1, and extend
straight in the front-rear direction Y1. Assuming that the central
portion 20 of the template 12 is a first rail, the second rails 51A
and 51B are arranged so as to sandwich the central portion 20. With
this configuration, the tibial insert trial 18 can slide in the
front-rear direction Y1 on the template 12, with the second rails
51A and 51B sandwiching the central portion 20 (the first
rail).
When the spacer 19 is not inserted between the template 12 and the
tibial insert trial 18, the pair of protrusions 53A and 53B are
received by the third upper face 28c of the template 12. At this
time, a gap is formed between the first spacer receiving portion 24
and the second spacer receiving portion 52.
The pair of protrusions 53A and 53B is arranged between the central
portion 20 and corresponding side end walls 29A and 29B of the
template 12, and is sandwiched between the central portion 20 and
the corresponding side end walls 29A and 29B. Side end wall
receiving portions 54A and 54B are formed in a rear portion of an
end portion, in the inward-outward direction X1, of the bottom
portion 50 of the tibial insert trial 18. These side end wall
receiving portions 54A and 54B are cutout portions configured to be
placed on the corresponding side end walls 29A and 29B of the
template 12, and extend forward and rearward.
Intermediate portions of the side end wall receiving portions 54A
and 54B each have a step portion, and the height position of rear
portions of the side end wall receiving portions 54A and 54B is set
higher than the height position of front portions of the side end
wall receiving portions 54A and 54B. The side end wall receiving
portions 54A and 54B are arranged to face the corresponding side
end walls 29A and 29B, and can be received by the side end walls
29A and 29B, respectively. Recessions 55A and 55B are formed on the
front side of the side end wall receiving portions 54A and 54B of
the tibial insert trial 18. When the tibial insert trial 18 is
placed on the template 12, the recessions 55A and 55B are
configured to expose the fixing pin insertion hole portions 30a and
30b, which are arranged at a front end of the template 12, upward
and forward.
In a state in which the tibial insert trial 18 has been placed on
the template 12, a central portion, in the inward-outward direction
X1, of the bottom portion 50 of the tibial insert trial 18 faces
the first upper face 28a of the template 12 in the up-down
direction, and a flat face formed in the central portion of the
bottom portion 50 includes the second spacer receiving portion 52
for receiving the spacer 19. The second spacer receiving portion 52
is a portion that has a substantially T-shape when seen from below,
and having a portion that extends in the front-rear direction Y1
and is formed between the pair of protrusions 53A and 53B, and a
portion arranged forward of the pair of protrusions 53A and
53B.
In a state in which the tibial insert trial 18 has been placed on
the template 12, the second spacer receiving portion 52 is
substantially parallel to the first spacer receiving portion 24 of
the template 12. When the tibial insert trial 18 has been placed on
the template 12, an insertion space 57, into which the spacer is to
be inserted, is formed between the template 12 and the tibial
insert trial 18. The insertion space 57 is formed by the spacer
receiving portions 24 and 52, the central portion 20 (the first
rail), and the second rails 51A and 51B. In the inward-outward
direction X1, the length of the insertion space 57 is set larger
than the length of a later-described body portion 61 of the spacer
19.
FIG. 17A is a perspective view showing the template 12 and the
tibial insert trial 18 before the spacer 19 is attached thereto.
FIG. 17B is a perspective view showing the template 12 and the
tibial insert trial 18 to which the spacer 19 has been attached.
FIG. 18A is a cross-sectional view showing a state in which the
spacer 19 is arranged between the template 12 and the tibial insert
trial 18, and shows a cross-section taken along a section
corresponding to a line XVB-XVB in FIG. 15A. FIG. 18B is a front
elevational view showing a state in which the spacer 19 is arranged
between the template 12 and the tibial insert trial 18.
Referring to FIGS. 17A and 17B, and 18A and 18B, the spacer 19 is
provided to adjust the height position of the tibial insert trial
18 relative to the template 12. Although a plurality of spacers
with different thicknesses of the body portion are provided in this
embodiment, the spacer 19 will be described as an example. Note
that other spacers have the same configuration except that the
thickness of the body portion differs from that of the spacer
19.
The spacer 19 is configured to be arranged in a partial area of the
template 12 in the inward-outward direction X1 of a patient and in
the central portion 20 of the template 12, and inserted between the
template 12 and the tibial insert trial 18. Constituents of the
spacer 19 other than a display portion of a later-described stopper
63 are formed symmetrically in the inward-outward direction X1.
The spacer 19 includes the body portion 61, which is formed into a
flat plate shape, and guide portions 62A and 62B and a stopper 63,
which are formed in a base end portion of the body portion 61.
The body portion 61 is formed into a flat plate shape having a
predetermined thickness, and extends in the front-rear direction
Y1. The thickness of the body portion 61 is fixed, except in a
leading end portion. The length of the body portion 61 in the
inward-outward direction X1 is set smaller than the length of the
first spacer receiving portion 24. A leading end of a central
portion of the body portion 61 in the inward-outward direction X1
has a shape that is recessed forward. Leading ends at both ends of
the body portion 61 in the inward-outward direction are formed by
tapered portions 64A and 64B. The tapered portions 64A and 64B are
leading end portions of the spacer 19 in the inserting direction in
which the spacer 19 is inserted into the insertion space 57 between
the template 12 and the tibial insert trial 18.
The tapered portions 64A and 64B are formed into shapes that are
tapered and decrease in thickness toward the leading end of the
spacer 19. In the inward-outward direction X1, the length of the
spacer insertion space 57 is set larger than the length of the body
portion 61 of the spacer 19. When the spacer 19 is inserted into
the insertion space 57, the tapered portions 64A and 64B are first
inserted into the insertion space 57. Then, the gap between the
first spacer receiving portion 24 (the first upper face 28a) of the
template 12 and the second spacer receiving portion 52 of the
tibial insert trial 18 is expanded by the tapered portions 64A and
64B, and then, a majority of the body portion 61 of the spacer 19
is inserted into the insertion space 57.
During this inserting operation, the guide portions 62A and 62B are
configured to respectively slidably mate with the rails 58A and 58B
formed in the central portion 20 of the template 12. The rails 58A
and 58B are formed in portions in which the template 12 and the
tibial insert trial 18 face each other. In this embodiment, the
rails 58A and 58B that extend in the front-rear direction Y1 are
formed in the two end portions, in the inward-outward direction X1,
of a front end portion of the central portion 20 of the template
12. The rails 58A and 58B are formed into inclined shapes that
extend outward in the inward-outward direction X1 as they extend
upward (from the third upper face 28c toward the first upper face
28a). The rails 58A and 58B form a reverse tapered shape as a whole
when seen from the front, and the gap therebetween expands upward.
Note that, the rails 58A and 58B are not formed in the portions of
the central portion 20 of the template 12 other than the front end
portion thereof, as shown in FIG. 3.
The guide portions 62A and 62B of the spacer 19 are formed into
hook-shaped portions that are formed in an outer end portion, in
the inward-outward direction X1, of the base end portion of the
body portion 61. The guide portions 62A and 62B extend downward
from the body portion 61, and form a reverse tapered shape such
that the gap therebetween narrows downward. After a portion of the
spacer 19 has been inserted into the insertion space 57, the guide
portions 62A and 62B slidably mate with the corresponding rails 58A
and 58B. If, in this state, the spacer 19 is further inserted into
the insertion space 57, the stopper 63 is received by a cutout
portion 18c of the tibial insert trial 18. Thus, insertion of the
space 19 into the insertion space 57 is complete.
The stopper 63 is arranged in the center, in the inward-outward
direction X1, of the base end portion of the body portion 61. The
stopper 63 is formed into a block shape. A display portion is
formed in a front face of the stopper 63, the display portion
displaying, by means of a mark or the like, the amount of change in
the total thickness of the template 12 and the tibial insert trial
18 when the spacer 19 is inserted in the insertion space 57. For
example, if "+1 mm" is displayed on the display portion, the
thickness of the body portion 61 of the spacer 19 is thicker, by 1
mm, than the thickness of the insertion space 57 in a state in
which the spacer 19 is not inserted therein. In this case, if the
spacer 19 is inserted into the insertion space 57, the total
thickness of the template 12 and the tibial insert trial 18
increases by 1 mm. The stopper 63 is fitted to the cutout portion
18c formed in the front end portion of the tibial insert trial 18.
The cutout portion 18c is a cutout portion that is open forward and
upward. As a result of the cutout portion 18c receiving the stopper
63, the spacer 19 is restricted from being further inserted into
the insertion space 57.
A tilt restriction mechanism 70 is formed in a state in which the
tibial insert trial 18 has been placed on the template 12 and the
spacer 19 has been inserted in the insertion space 57. The tilt
restriction mechanism 70 is provided to restrict tilting of the
tibial insert trial 18 relative to the template 12 around an axis
of the tibia 100 that extends in the front-rear direction Y1. In
this embodiment, the tilt restriction mechanism 70 is formed in
front portions of the template 12, the spacer 19, and the tibial
insert trial 18.
Referring to FIG. 18B, the tilt restriction mechanism 70 includes
first tilt restriction portions 71A and 71B, which are formed on
the upper face side of the template 12, second tilt restriction
portions 72A and 72B, which are formed on the lower face side of
the spacer 19 and can mate with the first tilt restriction portions
71A and 71B respectively, third tilt restriction portions 73A and
73B, which are formed on the upper face side of the spacer 19, and
fourth tilt restriction portions 74A and 74B, which are formed in
the tibial insert trial 18 and can mate with the third tilt
restriction portions 73A and 73B, respectively.
The first tilt restriction portions 71A and 71B are formed by the
aforementioned rails 58A and 58B, respectively. The second tilt
restricting portions 72A and 72B are formed by the aforementioned
guide portions 62A and 62B. Thus, the first tilt restriction
portions 71A and 71B and the second tilt restriction portions 72A
and 72B also serve as a rail mechanism. The shapes of the first
tilt restriction portions 71A and 71B are formed so as to match the
shapes of the second tilt restriction portions 72A and 72B, when
seen from the front.
The third tilt restriction portions 73A and 73B are formed in
respective end portions, in the inward-outward direction X1, of the
stopper 63 at a base end (front end) of the spacer 19. The third
tilt restriction portions 73A and 73B extend in the front-rear
direction Y1, and are formed into inclined shapes that extend
outward in the inward-outward direction X1 as they extend upward
from the body portion 61. When seen from the front, the third tilt
restriction portions 73A and 73B form a reverse tapered shape as a
whole, and the gap therebetween expands as they extend upward.
The fourth tilt restriction portions 74A and 74B are formed at
respective end portions, in the inward-outward direction X1, of the
cutout portion 18c of tibial insert trial 18. The fourth tilt
restriction portions 74A and 74B extend in the front-rear direction
Y1, and are formed into inclined shapes that extend outward in the
inward-outward direction X1 as they extend upward. When seen from
the front, the fourth tilt restriction portions 74A and 74B form a
reverse tapered shape as a whole, and the gap therebetween expands
as they extend upward. When seen from the front, the shapes of the
third tilt restriction portions 73A and 73B are formed so as to
match the shapes of the fourth tilt restriction portions 74A and
74B, respectively. Thus, the third tilt restriction portions 73A
and 73B and the fourth tilt restriction portions 74A and 74B also
serve as a stopper mechanism for preventing the spacer 19 from
excessively entering the insertion space 57.
Referring to FIGS. 17B and 18A, a position shift restriction
mechanism 80 is provided to restrict a position shift of the tibial
insert trial 18 in the inward-outward direction X1 relative to the
template 12, in a state in which the tibial insert trial 18 has
been placed on the template 12.
The position shift restriction mechanism 80 has a first shift
restriction portion 81, which is formed in the template 12, and a
second shift restriction portion 82, which is formed in the tibial
insert trial 18 and faces the first shift restriction portion 81 in
the inward-outward direction X1.
The first shift restriction portion 81 includes first inner shift
restriction portions 83A and 83B, which are formed at respective
end portions, in the inward-outward direction X1, of the central
portion 20 of the template 12, and first outer shift restriction
portions 84A and 84B, which are formed in side end walls 29A and
29B, respectively, of the template 12.
The second shift restriction portion 82 includes second inner shift
restriction portions 85A and 85B, which are formed by portions of
the pair of protrusions 53A and 53B of the tibial insert trial 18,
the portions forming the second rails 51A and 51B, and second outer
shift restriction portions 86A and 86B, which are formed in end
walls 18a and 18b of the tibial insert trial 18. The height of the
second inner shift restriction portions 85A and 85B from the bottom
portion 50 of the tibial insert trial 18 is set larger than the
thickness of the spacer 19. Thus, even when the spacer 19 has been
inserted in the insertion space 57, the second inner shift
restriction portions 85A and 85B sandwich the first inner shift
restriction portions 83A and 83B in the inward-outward direction
X1.
The length over which the first outer shift restriction portions
84A and 84B face the second outer shift restriction portions 86A
and 86B in the up-down direction is set larger than the thickness
of the spacer 19. Thus, even when the spacer 19 has been inserted
in the insertion space 57, the first outer shift restriction
portions 84A and 84B sandwich the second outer shift restriction
portions 86A and 86B in the inward-outward direction X1. The second
outer shift restriction portions 86A and 86B are sandwiched by the
first outer shift restriction portions 84A and 84B in the
inward-outward direction X1. According to the above configuration,
the tibial insert trial 18 is restricted from being displaced in
the inward-outward direction X1 relative to the template 12 by the
contact between the first inner shift restriction portions 83A and
83B and the corresponding second inner shift restriction portions
85A and 85B, or the contact between the first outer shift
restriction portions 84A and 84B and the corresponding second outer
shift restriction portions 86A and 86B.
A schematic configuration of the tibial trial attachment instrument
assembly 2 is as described above. Next, main points of a procedure
of an operation performed using the tibial trial attachment
instrument assembly 2 will be described. FIG. 19 is a flowchart
showing an example of a procedure of an operation performed using a
tibial trial attachment instrument assembly 2. Note that, when a
description is given with reference to the flowchart, diagrams
other than the flowchart will also be referenced as
appropriate.
When the tibial trial attachment instrument assembly 2 is used, an
operator first puts the template 12 onto the cut bone surface 102
of the patient's tibia 100 using the template handle 11, as shown
in FIG. 2 (step S1). Next, the operator fixes the studs 38a to 38d
of the keel punch guide 13 to the tibia 100 through the
corresponding stud insertion hole portions 27a to 27d (step S2). At
this time, the operator may fix the template 12 to the tibia 100
using fixing pins (not shown).
Referring to FIG. 5, next, the operator inserts, into the keel
punch guide 13, the drill 14 to which the stopper 15 has been
attached, and forms a preparatory hole in the proximal portion 101
of the tibia 100 (step S3). Next, referring to FIGS. 7 and 20A, the
operator connects the keel punch handle 17 to the keel punch 16 by
rotating the keel punch handle 17 by 90 degrees in the first
connecting direction D11 relative to the keel punch 16 (step S4),
and then, the operator drives the keel punch 16 into the proximal
portion 101 of the tibia 100 using the keel punch handle 17 and the
keel punch guide 13 (step S5).
Next, by rotating the keel punch handle 17 by 90 degrees in the
first disconnecting direction D12, i.e. the second connecting
direction D21, the operator cancels connection between the keel
punch handle 17 and the keel punch 16 through the first connection
mechanism 46, and connects the keel punch handle 17 to the keel
punch guide 13 through the second connection mechanism 47, as shown
in FIG. 20B (step S6). In this state, the operator removes the keel
punch handle 17 and the keel punch guide 13 from the tibia 100
(step S7).
Referring to FIGS. 17A and 17B, next, the operator attaches the
tibial insert trial 18 onto the template 12 to perform a trial
reduction (step S8). At this time, if tension of a patient's
ligament is weak, the spacer 19 is inserted between the template 12
and the tibial insert trial 18. When the spacer 19 is not inserted
between the template 12 and the tibial insert trial 18, a removal
tool (not shown) is inserted between the template 12 and the tibial
insert trial 18.
As described above, according to the present embodiment, the
template 12, the keel punch guide 13, the keel punch 16, the keel
punch handle 17, and the tibial insert trial 18 are prepared as a
single assembly. Accordingly, these instruments can be prepared
collectively, which is less laborious than in the case of preparing
these instruments separately. Accordingly, the amount of labor
required to attach the tibial insert trial 18 to a patient can be
further reduced.
Also, according to the present embodiment, the first connection
mechanism 46 can prevent the keel punch handle 17 from coming out
from the keel punch 16. Also, the keel punch handle 17 can be
disconnected from the keel punch 16 when necessary. This makes it
possible to suppress the case where the keel punch handle 17 and
the keel punch 16 become hindrances. As a result, the amount of
labor required to attach the tibial insert trial 18 to a patient
can be further reduced.
According to the present embodiment, connection and disconnection
between the keel punch handle 17 and the keel punch 16 can be
performed with a simple configuration in which the keel punch
handle 17 and the keel punch 16 are relatively moved in the first
direction D1. This makes it possible to further reduce the amount
of labor required to attach the tibial insert trial 18 to a
patient.
According to the present embodiment, the first direction D1 is a
rotational direction around an axis parallel to the axial direction
of the keel punch handle 17. According to this configuration,
connection and disconnection between the keel punch handle 17 and
the keel punch 16 can be performed with a simple configuration in
which the keel punch handle 17 and the keel punch 16 are relatively
rotated. This makes it possible to further reduce the amount of
labor required to attach the tibial insert trial 18 to a
patient.
According to the present embodiment, connection and disconnection
between the first protrusion 46a and the first projections 46b can
be performed with a simple operation, that is, relative movement of
the keel punch handle 17 and the keel punch 16.
According to the present embodiment, the keel punch handle 17 can
be connected to the keel punch 16 by causing the first protrusion
46a, which has a protruding shape, to be caught on the first
projections 46b formed within the tubular portion 161 of the keel
punch 16. Also, the aforementioned connection can be canceled by
rotating the first protrusion 46a relative to the first projections
46b.
According to the present embodiment, since the first protrusion 46a
can be received by the pair of projections 46b, the connection
strength between the keel punch handle 17 and the keel punch 16 can
be further increased. With this configuration, the operator does
not need to pay attention to the connection strength between the
keel punch handle 17 and the keel punch 16 when handling the keel
punch handle 17 to which the keel punch 16 has been attached. As a
result, the amount of labor required to attach the tibial insert
trial 18 to a patient can be further reduced.
According to the present embodiment, the second connection
mechanism 47 enables the keel punch handle 17 and the keel punch 13
to be integrally connected. This makes it possible to pull out the
keel punch guide 13 using the keel punch handle 17. Also, the keel
punch handle 17 can be disconnected from the keel punch guide 13
when necessary. This makes it possible to suppress the case where
the keel punch handle 17 and the keel punch guide 13 become
hindrances. As a result, the amount of labor required to attach the
tibial insert trial 18 to a patient can be further reduced.
According to the present embodiment, connection and disconnection
between the keel punch handle 17 and the keel punch guide 13 can be
performed with a simple configuration in which the keel punch
handle 17 and the keel punch guide 13 are relatively moved in the
second direction D2. This makes it possible to further reduce the
amount of labor required to attach the tibial insert trial 18 to a
patient.
According to the present embodiment, the second direction D2 is a
rotational direction around an axis parallel to the axial direction
of the keel punch handle 17. According to this configuration,
connection and disconnection between the keel punch handle 17 and
the keel punch guide 13 can be performed with a simple
configuration in which the keel punch handle 17 and the keel punch
guide 13 are relatively rotated. This makes it possible to further
reduce the amount of labor required to attach the tibial insert
trial 18 to a patient.
According to the present embodiment, connection and disconnection
between the second protrusions 47a and the second connected
portions 47b and 47c can be performed with a simple operation, that
is, relative movement of the keel punch handle 17 and the keel
punch guide 13.
According to the present embodiment, a single motion to displace
the keel punch handle 17 in one direction (the first disconnecting
direction D12 and the second connecting direction D21) relative to
the keel punch 16 and the keel punch guide 13 makes it possible to
simultaneously cancel the connection between the keel punch handle
17 and the keel punch 16 through the first connection mechanism 46
and connect the keel punch handle 17 to the keel punch guide 13
through the second connection mechanism 47. This makes it possible
to further reduce the amount of labor required to attach the tibial
insert trial 18 to a patient, through a reduction in the amount of
labor in handling the keel punch handle 17.
According to the present embodiment, the first connecting direction
D11 and the second connecting direction D21 are set to opposite
directions. According to this configuration, a configuration can be
realized that makes it possible to simultaneously perform an
operation to cancel the connection between the keel punch handle 17
and the keel punch 16 through the first connection mechanism 46 and
an operation to connect the keel punch handle 17 to the keel punch
guide 13 through the second connection mechanism 47. It is thus
possible to further reduce the amount of labor required to attach
the tibial insert trial 18 to a patient, through a reduction in the
amount of labor in handling the keel punch handle 17.
According to the present embodiment, even in a state in which the
space around the tibia 100 is small because the template 12 has
been attached to the patient's tibia 100, the connecting portion
11d of the template handle 11 can be removed from the template 12
through the passage 37 in the keel punch guide 13. This makes it
possible to more easily operate the template handle 11.
Accordingly, the amount of labor required to attach the tibial
insert trial 18 to a patient can be further reduced.
According to the present embodiment, the spacer 19 for adjusting
the height of the tibial insert trial 18 from the template 12 is
included in the tibial trial attachment instrument assembly 2. This
eliminates the need for a laborious operation to prepare the spacer
19, separately from other members of the tibial trial attachment
instrument assembly 2. Accordingly, the amount of labor required to
attach the tibial insert trial 18 to a patient can be further
reduced.
According to the present embodiment, the first connection mechanism
46 for connecting the keel punch handle 17 to the keel punch 16 is
arranged within the tubular portion 161 of the keel punch 16 that
is to be inserted into the patient's tibia 100. Since the tubular
portion 161 is configured to be inserted into the tibia 100, the
length of the tubular portion 161 in the axial direction and the
diameter thereof can be secured to some extent. This makes it
possible to sufficiently secure the space for arranging the first
connection mechanism 46 within the tubular portion 161.
Accordingly, the first connection mechanism 46 can be formed to
have a size that makes it possible to sufficiently secure the
connection strength between the keel punch handle 17 and the keel
punch 16. Furthermore, the degree of freedom in designing of the
structure (the first connection mechanism 46) for connecting the
keel punch handle 17 to the keel punch 16 can be further
increased.
According to the present embodiment, the first protrusion 46a can
be connected to the first projections 46b by inserting the
insertion end portion 45 of the keel punch handle 17 into the
tubular portion 161. This simple configuration of the first
connection mechanism 46 makes it possible to form the first
connection mechanism 46 to have a size with which the connection
strength between the keel punch handle 17 and the keel punch 16 can
be secured sufficiently. Furthermore, the degree of freedom in
designing of the structure (the first connection mechanism 46) for
connecting the keel punch handle 17 to the keel punch 16 can be
further increased.
According to the present embodiment, connection and disconnection
between the first protrusion 46a and the first projections 46b can
be performed with a simple configuration in which the keel punch
handle 17 and the keel punch 16 are relatively displaced.
According to the present embodiment, the first connection mechanism
46 has a connection structure using a protrusion (the first
protrusion 46a). This configuration makes it possible to further
increase the strength of the first protrusion 46a in the first
connection mechanism 46, by employing a simple protruding
shape.
According to the present embodiment, since the first protrusion 46a
can be received by the pair of projections 46b, the connection
strength between the keel punch handle 17 and the keel punch 16 can
be further increased.
According to the present embodiment, connection between the keel
punch handle 17 and the keel punch 16 through the first connection
mechanism 46 can be realized by inserting the keel punch handle 17
into the keel punch 16 until the first stopper 40 of the keel punch
handle 17 is received by the opening edge portion 161a of the
tubular portion 161, and thereafter displacing the keel punch
handle 17 relative to the keel punch 16. Thus, the amount of
insertion of the keel punch handle 17 into the keel punch 16 can be
defined by the second stopper 44.
According to the present embodiment, only a single component,
namely the spacer 19, is needed to adjust the height position of
the tibial insert trial 18 from the template 12. This makes it
possible to further reduce the number of components in the
configuration of the artificial knee joint replacement operation
instrument 1 for adjusting the height position of the tibial insert
trial 18. Also, the spacer 19 is arranged in a partial area of the
template 12 in the inward-outward direction X1 of a patient, and in
the central portion 20 of the template 12. This makes it possible
to shorten the length over which the spacer 19 comes into contact
with the template 12 and the tibial insert trial 18 in the
inward-outward direction X1. Accordingly, when an operator inserts
the spacer 19 between the template 12 and the tibial insert trial
18, the frictional resistance that the spacer 19 is subjected to
can be further reduced. This makes it possible to further reduce
the amount of labor required to attach the tibial insert trial 18
to a patient.
According to the present embodiment, the leading end portion of the
spacer 19 in the inserting direction includes the tapered portions
64A and 64B, which are formed into tapered shapes. This
configuration makes it possible to further reduce the force
required to insert the spacer 19 between the template 12 and the
tibial insert trial 18. Accordingly, the amount of labor required
to attach the tibial insert trial 18 to a patient can be further
reduced.
According to the present embodiment, in the inward-outward
direction X1, the length of the insertion space 57 between the
template 12 and the tibial insert trial 18 is set larger than the
length of the spacer 19. According to this configuration, the
spacer 19 does not need to be strictly positioned in the
inward-outward direction X1 relative to the spacer insertion space
57 when the spacer 19 is inserted into the insertion space 57, for
example. This makes it possible to further reduce the amount of
labor required to attach the tibial insert trial 18 to a
patient.
According to the present embodiment, when the spacer 19 is inserted
between the template 12 and the tibial insert trial 18, the spacer
19 can be inserted more accurately by being guided by the rails 58A
and 58B.
According to the present embodiment, the tilt restriction mechanism
70 is provided. According to this configuration, the tibial insert
trial 18 can be restricted from tilting by joining the template 12
to the tibial insert trial 18 via the spacer 19. This makes it
possible to further reduce the amount of labor required by an
operator to maintain the orientation of the tibial insert trial 18
on the template 12. As a result, the amount of labor required to
attach the tibial insert trial 18 to a patient can be further
reduced.
According to the present embodiment, the stopper 63 that defines
the position of the spacer 19 is formed at a front end of the
spacer 19. Since this stopper 63 is accommodated in the cutout
portion 18c of the tibial insert trial 18, the stopper 63 does not
become a hindrance around the template 12 when being accommodated
between the template 12 and the tibial insert trial 18. Also, the
stopper 63 can also be used as a portion of the tilt restriction
mechanism 70, which makes it possible to prevent the shape of the
tibial insert trial 18 in its periphery from becoming complex. This
makes it possible to further reduce the amount of labor required to
attach the tibial insert trial 18 to a patient.
According to the present embodiment, the position shift restriction
mechanism 80 is provided. According to this configuration,
engagement between the first shift restriction portion 81 with the
second shift restriction portion 82 can restrict the position of
the tibial insert trial 18 from being shifted in the inward-outward
direction X1 relative to the template 12. This makes it possible to
further reduce the amount of labor required by an operator to
maintain the orientation of the tibial insert trial 18 on the
template 12. As a result, the amount of labor required to attach
the tibial insert trial 18 to a patient can be further reduced.
According to the present embodiment, in the inward-outward
direction X1, the positions of the fixing pin insertion hole
portions 30a to 30f in the template 12 differ from the position of
the spacer 19. According to this configuration, the fixing pins 31
do not become hindrances when the spacer 19 is inserted between the
template 12 and the tibial insert trial 18 in a state in which the
template 12 has been fixed to the tibial 100 with the fixing pins
31. Accordingly, the fixing pins 31 do not need to be removed from
the template 12 during a height adjustment operation performed
using the spacer 19, and the amount of labor required to attach the
tibial insert trial 18 to a patient can be further reduced.
Although an embodiment of the present invention has been described
thus far, the present invention is not limited to the
above-described embodiment, and various modifications can be made
within the scope recited in the claims. For example, the following
modifications are possible.
In the above embodiment, the first direction D1 and the second
direction D2, which are rotational directions, have been described
as examples of the directions in which the first connection
mechanism 46 and the second connection mechanism 47 are operated.
However, this need not be the case. For example, the first
direction D1 and the second direction D2 may alternatively be
helical directions, or may be straight directions. Also, a
configuration may also be employed in which a lever that passes
from a base end to a leading end of the keel punch handle is
provided, and the keel punch handle is connected to or disconnected
from the inside of the tubular portion of the keel punch by
displacing this lever upward or downward.
INDUSTRIAL APPLICABILITY
The present invention is broadly applicable as an artificial knee
joint replacement operation instrument used in an operation for
replacing a patient's knee joint with an artificial knee joint.
DESCRIPTIONS OF REFERENCE NUMERALS
1 Artificial knee joint replacement operation instrument 2 Tibial
trial attachment instrument assembly 11 Template handle 12 Template
13 Keel punch guide 16 Keel punch 17 Keel punch handle 18 Tibial
insert trial 19 Spacer 37 Passage 46 First connection mechanism 46a
First protrusion 46b First projection (first connected portion) 47
Second connection mechanism 47a Second protrusion 47b, 47c Second
connected portion 100 Tibia 131 Tubular portion of keel punch guide
161 Tubular portion of keel punch D1 First direction D2 Second
direction
* * * * *